Simulation of $^{75}$Se Encapsulated Sources for Their Potential Use in Brachytherapy

The physical characteristics of the 75Se radionuclide make it a promising gamma radiator for use as a brachytherapy sealed source. This radionuclide combines relatively low-energy photon radiation emitted during decay with a sufficiently long half-life (approximately 120 days) and the possibility of obtaining high specific activity. All this makes this radionuclide attractive for automated injection brachytherapy. The aim of this work was to study the dosimetric characteristics of $^{75}$Se for its potential use in high and medium dose rate brachytherapy. According to the TG-43 formalism, the radial dose function g(r) and the anisotropy function $F(r, \theta)$ are calculated. $^{75}$Se as a radionuclide for sealed source brachytherapy has many advantages over widely used isotopes and can serve as an alternative to iridium sources.